Centrifugal casting machine



' G. A. WIECHERT CENTRIFUGAL CASTING MACHINE Dec. 28 1926.

2 Sheets-Sheet l Filed Sept. 28, 1922 MEUR-EE.

MM5 W G. A. WIECHERT CENTRIFUGAL CASTING MACHINE Filed Sept. 28, 1922 2 Sheets-Sheet 2 MR??? 44 lrsuaall] 4A 36 A TTORNE Y GEURQE EL. WMC'WRT, @F NEW Yml, lil.. l2".

application ala septemberaa, iosa. anni no. autres.

Mly invention relates to centrifugal casting machines ola type suitable for general use, and particularly ladapted for making'` Figure l shows my improved castingmachine, partly in rear elevation and partly in section.

Figure 2 is a fragmentary plan showing the molding dash and means toi-,supporting the same upon the shaft.

,Figure 3 is a side elevation of the flash.

'Figure 4 lisa fragmentary view, partly a' side elevation and partlp` a section,` ot the mechanism appearing in igure l.

Figure 5 is an elevation of the sprue plate, and parts carried thereby.

.Figure 6 is a longitudinal sectiontlirollgh Vthe dash and. arts' contained therein, ready to receive the investiture, and is taken upon the line 6-6 otFigure 7, looking in the direction indicated hy the arrows.

Figure 7 is a plan view ot theA flask and the spr-ue plate mounted thereupon and used in connection therewith.

Figure 8 is a iront elevation ot the dash and sprue plate.

' liigure @is a sectionon the line 9 9 of Figure l, looking iur-the direction indicatedhy the arrows, and showing a core and other parts supported Within the j Fire 10 is longitudinal section through the tlaslr and its contents, when ready for molding.' f r l Suppoitedjhy-a tahleltl is a casing ll, provided with a pair ot lugs 12 tor engaging the'upper surface ot the table, as shown lmore particularly in Figures l and el. flhe casing is provided with a downwardly er,- tending member 13, carrying 'a laterally extending portion lll. A set screw 15 extends through the portion 14, and is used for securing 'the casing upon the table 10. The casing is provided with bolts 16, which in this instance are four in number, and is `turther provided with-a laterally extending portion 17 of substantially tubular forni,

constituting a hearing. revoluhle shalt 17a extends through the hearing 17 and into the casing. Mounted rigidly upon the Vshaft 1T' is a cranlr arm 18, carrying a handle 19. These parts are so' arranged that the operator, by graping the handle 19 and turning the cranlr 18, causes the yrotation of the shaft i ll.- Mounted rigidly upon the shaft 17al and located within the casing ll is a gear Wheel 20 ota rather large size, as :may he understood troni Figure l. Il; pinion 2l,

located Within the upper part ot the casing, engages the gear wheel 2@ and is turned by the rotation thereof. 'lhe casing is provided With two hearings 22 and 23, in axial alinement with each other, a each having a substantially tubular torni. Ar revoluble shaft 2t is supported hy these. hearings,

A' and carries the pinion 2l-wherehy the shalt 1s driven. The ratio ot the gearing, in thc 'mechanism here shown, is 13 to l. An oil cup 25, mounted upon the casing, is used for luhricatin the inion 21. and shaft 24:.

The das use for casting appears at 31, and carries 'a lug 26provided with a small hole 27. The lug is integral with` the flask,

and extends laterally outward from it.

The shaft 2d is provided at its outer or` freeend with a slot 28, so4 arranged that the lug 26 may he itted snugly into the slot,l thus supporting lthe dash directly upon the end of the shaft. 'lhe shaft 241 is provided with a hole 29, extending axially through it and so positioned as to register with the hole 27 through the lu 1 26 when this lug is tted into the slot.; Cotter pin. 3d extends through the holes 27 andv 29., and holds the lug 26 and the shalt 2d rmly together.

A weight 32 Ais provided with a collar 33 integral with it,'and is further provided with a set screw 33a, whereby it is detachahly mounted upon the shaft 2t..

'lhe tlash is cut away at its top, reckoning from the position indicated in Figure 9, so

"as to torrn a step 3l. as shown in this figure.

notches serving the general purpose of air,

vents. The sprueplate has a. downwardly rai lli

lill

lllll flask, so that the tonguel v3 extendin tongue 37, the lower end of which 1s provi ed with a slot, adapted to hold a small quantity ofwaxBS as indicated `in Figure 5. Thev tongue 37 is rather wide, as indicated in 'this figure, and thus presents a 'flat surfacel adapted for holding anothen charge of wax 40, as shown. A saucer 39,A

made preferably of metal, is detachably secured upon the tongue 37 by aid of the wax 40,- as indicated in Figure 5. For this purpose thesaucer 39 is Simply pressed against the. wax. lOwing to the plasticity of the wax, the saucer 39 may be moved slightly in relation to the tongue 37. This is done by the Voperator simply pressing with his lingers uponthe saucer 39, and at the same time slowly pushingV the saucer edgewise. Thus the saucer can be secured by aid of the wax, in an infinite number, of slightly different ositio'ns, upon-the tongue 37. The saucer 1s detachable from the tongue 37, as it is not held thereto by anything except the wax. A core 41- may be supported upon the lower end of the tongue 37 by means of the wax 38, as may. be understood from Figure 6. This core 41 may support a wax facing 42 asshown in this gure. e

Wax threads 43 and 44 are connected with the filling 42v and `corel 41. These wax threads, and the lling 42 are used as hereinafter described. The wax threads 43 extend out to the notches 36, and the wax threads '44 extend outto the notch 35.

l will next describe the manner of preparing investiture to be used in the iiask 31.. The sprue plate 34, carrying various parts as shown in Figure 6, is lifted upwardly from the flask 31, and the flask is then filled with a semi-liquid or plastic material capa- `f`le of hardening or setting and also capable of withstandin this purpose` may use either plaster ot Paris or any of the various compositions suitable for use in preparing ask molds. .While the materialis still soft the sprue plate 34 is' gently lowered and rested uyon the top of the 4the saucer 39, the core 41 and other parts are submerged 1Within the filling, which extends entirel to the top of the flask and which. because o' the shape of the sprue plate, now has a step formation. The filling is next allowed to set and thus to harden. This done, the flask and its contents are subjected to a moderate heating for some little time. This heating melts and dries out all of the wax, wherever located. within the iask.4 Next the sprue plate 34 is lifted and removed, carrying with it of course the tongue 37 but leaving behind it the saucer 39, the saucer being now freed from the tongue by the disappearance of the wax. The operator next removes the saucer 39. This -leaves the flask and its contents in the condition indicated in Figu filling is shown at 45, the core 41 now being a high temperature. Forv re 10. `The partially embedded'within it. A cavity 46 partially bounds the filling 41, occupying the position previously occupied by the wax facing 42 and shown in Figure 6. Air passages 47 and 48' communicate with the lling 41, and occupying positions previously occupied by the wax threads 43 and 44. These air passages lead to the notches 35 and 36.

The iask and its contents as shown in Figure -1() being nowl ready for molding, the dask is placed in position upon the machine in the manner above described. lihe handle 19 has prevlously been turned into such osition that the flash, when thus in position upon the machine, extends obliquely downward from the shaft 24, as indicated in Fighre l.' Nexta charge of gold or other metal to be used in casting is placed within the cavity 49, and is then heated, by a blow pipe or in any other appropriate manner, until melted and of the proper temperature for casting., v Y,

This done, the operator turns the handle 19, so that the shaft 24 begins its rotation instantly, and the molten mtal is by 'centrifugal force driven outwardly and thus toward the bottom of the Hash, the air contained within the dash making its escape through the passages 47 and 48. Finally the lling 46 is removedV and broken, the nished casting, corresponding to the cavity 46 being thus recovered.

.ln the construction above described l do not use any Crucible, as none is necessary. rlhe melting of the metal used in casting, the flow of this metal after'it is melted, and its hardening after being formed into the casing', are ste s all of which take place altogether withln the body of the flask.

lt will be noted that the distance from the shaft 24 to the outer or bottom end of the fiask is shorter than the length of the ask.

ln fact the flask is partially cut awaygin order to accommodate the shaft 24, as may 4be understood from Figures 1 and 2. Such being the case, the iiask may be lconsidered as extending directly outward from the shaft; or to state the matter in another way. the liask, reckoning from its outer or bottom end, reaches inwardly beyond the center of the shaft. Thus l use no casting arm whatever, or any equivalent for a casting arm.

rlhe expulsion ofthe air from the mold is l by this arrangement quite effective, in that the air .,by traveling radially inward toward the center of rotation of the flask..has a number of unobstructed paths. The molten metal, forced outwardly by centrifugal force,

displaces the air in the mold, andithus drivesthe same inwardly or toward the center of rotation, the air thus .being discharged inwardly as regards the centerofrotation.

As all parts of the machine are preferably made small and light, the ratio of the gearlng may be relatively high. While in thisv particular instance the ratio is 13 to 1, any1 other suitable ratio may be employed. find that with the ratio of 13 to 1, and with the various revoluble parts made light and small, a relatively high speed of rotation may be instantly conferred upon the flask, so that there is no possibility of the molten metal traveling in the wrong direction due to any lag in speeding up the flask. The operator turns the handle in a clockwise direction and the flask rotates in the opposite direction, so that the molten metal has no chance to spill out of the flask.

My machine is iwell adapted for small castings of many kinds, including dentures and many forms of jewelry.

I do not linit myself to t e precise mechanism shown, as variations may be made therein Without departing from the spirit of my invention,

Having thus described my invention what I claim as new, I desire to secure by Letters Patent is as :follows:

1. In a. moldingapparatus the combination of a sprue plate provided with a portion for extending into a flask, and a member separate from said ortion and detachably carried thereby, or the purpose of forming an impression in an investiture to be carried by the flask.

2. A device of the character described comprising a flask and a sprue plate fitted thereto, said sprue plate being provided with a tongue so positioned as to extend into the flask when the sprue plate is in position thereupon, and a member detachably mounted upon said tongue and having the proximate form 4of a saucer.

A device of the character describ comprising a flask and a sprue' plate fitted thereto, said sprue plate being provided with a portion extending to the flask when the sprue plate is in position upon the flask, means for supporting a core upon said portion thus extending into the flask, and a member mounted upon' said portion and movable relatively thereto, for the purpose of making an impression upon a filling within the flask.

4. As an, article of manufacture, a sprue plate provided with an extending portion and with means for detachably supporting upon said extending portion a core to be disconnected therefrom, and means for holding said member upon said portion, so as to allow said member to be shifted slightly in position relatively to said extending portion,

` portion, and a member carried by said sprue the for the purpose of aflectinfr the form of an investiture within said flas 5. The combination of a flask and a filling contained therein, said filling containing a corey and a cavity partially bounding said core'in order to form a casting connected with the core, said filling also containing a cavity communicating with `first mentioned cavity for the purpose of holding a quantity of metal, While the same is being melted in order to form a casting.

6. The combination of a flask and a filling contained therein, said filling being provided with' a cavity for forming a casting and with an air passage for venting said cavity as the latter is filled with molten metal, said filling being also provided with a cavit communicating Wit said first-mentione caivity for the purpose of holding a quantity of metal while the same is being melted.

7. The combination of a flask and a fillin carried thereby, said filling being provided with a cavity in which the casting is to be formed and further provided with a core partially bounding said cavity, and with air passages communicating with said core and said core and said cavity, said filling being also provided with a portion formed into a cavity for supporting a quantity of metal While the same is being melted, and before it is discharged into first mentioned cavity.

8.*In a device of the character described a sprue plate rovided with a tongue, a quantity of wax a hering to said tongue, and an impression member adhering to said wax.

9.l In a device of the character described a sprue plate provided with an extending plate for the purpose of afectin orm of a mold to be made by aid o the sprue plate, and means for enabling the operator to shift the position of said member relative to said extending ortion in order to vary the form of said mol.

10. In a device of the character described the combination of a flask and a sprue plate mounted thereupon, saidsprue plate bein provided with a tongue extending into sai flask and further provided with a slot extending into said tongue for the purpose of carrying a small quantity of Wax.

11. A device of the character described comprising a flask and a sprue late fitted thereupon, said flask and sprue p ate having together a step formation.

GEORGE A. WIECHERT.

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